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A. ANDRENQ ADJUSTABLE SUPPORT FOR SCHOOL FURNITURE. No. 548,498. PatentedOct. 22, 1895.

II 7,, llIII-- -IIIIIIIlIlIl' "(DIM E GRAHAM. PNOYO UTNIIWASNINGWIJII UNITED STA ES PATEN ifQ m- ALBAN ANDREN, OF BEVERLY, ASSIGNOR TO THE CHANDLERADJUSTABLE CHAIR AND DESK COMPANY, OF BOSTQN, MASSACHUSETTS.

ADJUSTABLE SUPPORT FOR SCHOOL FURNITURE.

SPECIFICATION forming part of Letters Patent No. 548,498, dated October 22, 1895.

Applicationfiled May 23,1895. I

To @ZZ whom it may concern:

Be it known that I, ALBAN Annnnn, a citizen of the United States, and a resident of Beverly, in the county of Essex and State of Massachusetts, have invented new and useful Improvements in Adjustable Supports for School Furniture, of which the following, taken in connection with the accompanying drawings, is a specification.

This invention relates to improvements in adj ustable supports for school furniture such as desks, chairs, seats, &c.-and it is designed for the purpose of adjusting from time to time the furniture to the heightor size of the scholar for which it is to be used.

The invention is carried out as follows, reference being had to the accompanying drawings, wherein- Figure 1 represents a side elevation of my improved adjustable support, shown as applied to a chair or seat. Fig. 2 represents a rear elevation of the invention. Fig. 3 represents a vertical longitudinal section of Fig. 2. Fig. 4. represents a cross-section on the line 4 at, shown in Fig. 2. Fig. 5 represents a crosssection showing a modified construction.

Similar letters refer to similar parts wherever they occur on the different parts of the drawings.

A represents the flange of the upwardlyprojecting base portion A, which is preferably made semicircular or curved in section, but may be made of other sectional form without departing from the essence of my invention.

B is the vertically-adjustable shank secured at its upper end to the furniture C in any suitable manner. Said shank B is preferably made tapering from top to bottom-that is, thicker at its upper portion as compared with the lower endbut may be of equal thickness throughout its length,if so desired. The shank B is adj ustably clamped against the interior of the base portion A by means of an eccentric or cam D, having end trunnions d d, j ournaled in slotted perforated or hooked ears A" A", as shown in the drawings.

The cam D may be toothed and adapted to interlock with a corresponding toothed face or faces b on the rear side of the adjustable Serial No. 550,320. No model.)

shank B, as shown in Figs. 1, 2, 3, and 4, or the cam and the face of the said shank may be smooth, as shown in Fig. 5.

In Figs. 2, 3, and 4 1 have shown the adjustable shank B as being V-shaped in crosssection, with inclined bearing-surfaces b 29, adapted to bear against corresponding inclined surfaces on the interior of the base A, and also represented the said shank as having a front or rib 6'', adapted to fit against the middle interior portion of the said base A.

In Fig. 5 I have represented the cam D as having a pair of tapering cam-faces d (1', adapted to fit into correspondingly-shaped recesses in the rear of the shank B.

By using one or more tapering faces on the cam and a correspondingly-shaped shank the latter is more firmly locked in position and prevented from moving laterally after being adjusted and locked.

In practice I prefer to turn the cam D, in the act of adjusting it and the shank B, by means of a detachable rod or handle E, adapted to be inserted in a recess b in the cam D, as shown in Figs. 2 and 3.

If it is desired to adjust the shank B relative to its base portion A, all that is necessary to do is to turn the cam D slightly in the direction of the arrow shown in Fig. 3, causing it to be unlocked from the said shank and the latter from said base portion, after which the shank may be adjusted up or down to suit requirements and clamped firmly in position relative to the base portion A simply by turning the cam D in a direction opposite to that shown by the arrow in Fig. 3. The downward pressure exerted on the seat by the occupant will tend to still more firmly secure the shank to the base portion.

The device is very simple in construction, is easily adjusted, and by its means a most powerful holding grip is produced between the cam, shank, and base portion.

What I wish to secure by Letters Patent ICO justable shank seated within said guide and having one or more V-shaped grooves, and inclined bearing surfaces, said bearing surfaces acting against the inclined faces of the guide a pivoted cam journaled upon the stationary base portion and adapted to clamp the shank, and one or more V-shaped projections upon the periphery of the cam which engage with the grooves in the shank, substantially as described. 7

2. In an adjustable support for school fur niture, the combination with the stationary base portion provided With an upwardly extending concaved guide, of an adjustable shank seated Within said guide and provided upon its front face With one or more V-shaped grooves, and a pivoted cam journaled upon the stationary base portion and adapted to clamp the shank, said cain being provided upon its periphery with one or more V-shaped projections which engage with the grooves in the shank, substantially as described.

3. In an adjustable support for furniture, the combination with the stationary base portion provided with an upwardly extending guide, of an adjustable shank sliding within said guide and provided upon its front face with one or more grooves, and a pivoted cam adapted to clamp the base, said cam being provided upon its periphery with one or more projections which engage with the grooves in the shank, substantially as described.

In testimony whereof I have signed my name to this specification, in the presence of two subscribing witnesses,on this 20th day of May, A. D. 1895. v

ALBAN ANDREBT.

\Vitnesses:

LAURITZ N. MoLLnn, CHARLES A. HARRIS. 

